Name: ________________________________
ENZYME QUESTIONS
1. Why do cells contain many different enzymes?
(A) Enzymes are temperature specific.
(B) Enzymes are specific in their action.
(C) Enzymes are sensitive to pH changes.
(D) Enzymes are sensitive to substrate concentration
2. The diagram shows one example of enzyme action as demonstrated by the ‘Lock and Key’
model.
Which part of the diagram represents the substrate?
3. Which statement best describes the relationship between proteins and polypeptides?
(A) Proteins are composed of polypeptides.
(B) Polypeptides are composed of proteins.
(C) Proteins, unlike polypeptides, are composed of amino acids.
(D) Polypeptides, unlike proteins, are composed of amino acids
Name: ________________________________
4. Which of the following sequences most correctly represents the results of a reaction
involving an enzyme?
(A) P1 S
P2 E
(B) S E P1 P2
(C) P1 P2 E S E
(D) S E P1 P2 E
Name: ________________________________
6. Students conducted a large first-hand investigation into enzyme activity. The aim in the
report is shown.
Aim: To determine the optimum pH of four different enzymes.
How many independent variables were in this first-hand investigation?
(A) 1
(C) 4
(B) 2
(D) 5
7. Rennin is an enzyme found in the stomach of young mammals. Rennin curdles the milk
drunk by the mammal and allows the milk solids to stay longer in the stomach to be further
digested. Students conducted an investigation into rennin activity. They bubbled different
volumes of carbon dioxide gas into milk samples. Each sample was 50 mL and was kept at a
constant temperature. The students then added rennin to each milk sample and recorded the
time taken for the milk to curdle.
(a) Account for the students’ calculated average time for 300 bubbles of CO2. (2)
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(b) Explain the results of this experiment. (4)
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Name: ________________________________
8. The graph below shows the results obtained from testing the activity of a bacterial enzyme.
(a) Name ONE variable, other than temperature, that would have been controlled in
the experiment. (1)
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(b) For what temperature range does the enzyme display the maximum rate of
change in activity? (1)
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(c) Account for the activity of the enzyme at the parts of the graph labelled A, B, C and D. (4)
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(d) Based on the information in the graph, suggest the type of environment in which
these bacteria might survive. (1)
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